Method of producing wrought iron



Patented May 29, 1934 METHOD or PRODUCING WROUGHT IRON 7 Fritz Singer, Nuremberg, Germany, assignor to Tubus A. G., Zurich, Switzerland No Drawing. Application July 26, 1930, Serial N0.

471,079. Renewed June 14,

June 25, 1928 1933. In Germany 4 Claims. (Cl. 75 -4.?

My invention pertains to an improved method of producing iron and steel containing non-metallic materials, which iron and steel has the chief properties of wrought iron as heretofore produced by the puddling process, though it may have special properties peculiar to itself, and will therefore'be'generically referred to hereinas wrought iron.

Wrought iron and steel, as heretofore produced 10 by the puddling and kindred processes, are, of

course, essentially superior to ingot iron, produced by melting, for a number of purposes, for example when a high resistance to corrosion is required. The ordinary puddling process, however, requires a great deal of hand work, does not admit of large scale production, and is costly, and although endeavors have been made of late years to perform the puddling operation mechanically, with the idea of avoiding hand work and render- .ing large scale production possible, the product has remained relatively expensive. For these reasons puddled iron and steel have been largely superseded by open-hearth or Bessemer iron in uses to which the puddled iron and steel would be well adapted.

In an endeavor to obtain high-grade wrought iron having the desired properties it has been proposed to produce it by adding open-hearth or Bessemer iron either in a fluid state or in a finely granulated or comminuted condition to a bath of molten slag maintained at or above a welding temperature. As the material enters the bath, being raised thereby, if in a granulated or comm'nuted condition, to welding temperature, it is formed into a ball, either as it drops through the bath or by hand or mechanical puddling if desired. The ball is removed and squeezed and otherwise treated in the usual manner. However, this process still remains expensive, as it requires open-hearth or Bessemer iron as its foundation material. Moreover, it is subject to practical difiiculties, notably in obtaining a homogeneous distribution of the slag.

It is an object of my invention to provide a '45; process which will overcome the difilculties heretofore encountered and which will enable wrought iron and wrought iron articles to be produced with greater ease and economy than has been possible by the processes heretofore known. It 50 is a further object to provide a process of producing wrought iron which will enable to be incorporated into the iron such quantities, within reasonable limits, of non-metallic materials as will produce various desired results. In carrying my invention into effect, I mix new eArsN-r craze E 1 A finely divided iron or comminutedspongy iron a convenient form such as that of a billet, plate or the like. I then heat the body towelding tem perature and work it. In the term ,work as used herein and in the appended claims, rolling; forging, drawing, pressing, extruding, and kindred mechanical processes are intended to be included. The resulting product has the chief properties of wrought iron as heretofore produced by the puddling process, and has, in some manners of carrying out the process, useful properties peculiar to itself.

The iron employed in starting the process can be iron in powder form as produced by electrolysis or by the reduction of ore in solid state (spongy iron), or by decomposition of gaseous compounds of iron etc. comminuted iron scrap, such as machine turnings, is also adapted for the purpose. Powdered iron silicate slag is preferably used as the non-metallic material, though other materials found to have on the ferrite grain a purifying effect equal to or greater than that of iron silicate, might be employed. By adding carbon to the non-metallic ingredient of the m'xture (for instance to iron silicate slag powder) wrought iron having a higher percentage of carbon than usual is obtained. Instead of iron silicate slag there may be used materials productive of iron silicate slag upon being heated, in accordance with the practice known in the art, as shown, for example, in United States Patents Nos. 1,713,887 to Briggs and 1,675,867 to Pike.

Thus an important advantage of the process of my invention, in addition. to its result of produclng wrought iron more economically than has heretofore been possible, is that it permits that there be incorporated into the iron any quantity, within reasonable limits, of such non-metallic materials as may be desired to give various special properties, whereas in the usual methods of producing wrought iron the quantity of slag employed cannot be materially varied.

The following is a specific example, given for purposes of illustration merely, of the numerous manners in which my invention can be practiced:

in the production of wrought iron articles intended for use where resistance to corrosion is especially desired, I mix intimately comminuted spongy iron with powdered iron silicate slag in the proportions of 96% iron and 4% of the iron pacted body or billetof a density substantially asgreat as that of. wrought iron: made: by the:

puddling process. Furthermore, the pressure produces such compactness that the relative positions of the particles of iron and slag in the body remain fixed during the next step in the process. The billet thus obtained is heated to welding temperature and extruded: in an ext-rm sion press to produce, for instance, a tube. The-- properties of the metal of which. such. tube is.-

composed are in the main those. of wrought-iron produced by the puddling process. As the great pressure to which the mixture is subjected preserves through the heating step the original intimate distributionof the. componentsv in. the mixture an increased resistance. to. corrosion is obtained;

I claim:

1 The. processor. manufacturing wrought iron which includes thesteps of. mixing. iron in. powder form.with=.a.powder of ironsilicate slag and. carbon, then. compressing, said mixture to form; a. compacted. body, then-heatingsaidbody toweld ing temperature and then mechanically working said body.

2. The process of producing articles of wrought iron which includes the steps of mixing discrete particles of iron with powdered iron silicate slag, then compressing, said mixture to form. a. compacted;body in whichthelrelativepositions of the particles of iron and slag remain fixed through the next step, then heating said compacted body to. welding temperature, and then working said body to form the desired articles.

3*; 'I'heprocesszofi'pmducing articles of wrought iron which includes the. steps of mixing discrete particles of iron. with powdered iron silicate slag, then compressing said mixture to form a compactedbody ofi high: density, then heating said compacted; body to welding temperature, and then working said body to form the desired articles.v

4. The process of producing articles of wrought iron which includes; the: steps; of discrete particles-pf. iron; with powdered iron silicate. slag,

then; compressing: mixture: to form: a; com-e pacted body of a density substantially as; great.

as. that. 01. wrought irom made: by" the paddling:

process, then: heating; said. compacted body in:

welding. tempera-ture-,. and. them call! working said body to form the desired articles FRITZ; 

